JP7127432B2 - optical devices and electronic devices - Google Patents

Description

The present invention relates to optical devices and electronic equipment.

2. Description of the Related Art Conventionally, an optical device (tunable interference filter) having an optical member (optical multilayer mirror) in which high refractive layers and low refractive layers are alternately laminated is known (see, for example, Patent Document 1).
The tunable interference filter described in Patent Document 1 has a configuration in which a lower mirror composed of an optical multilayer mirror and an upper mirror composed of an optical multilayer mirror are arranged opposite to each other with a gap therebetween. In such a tunable interference filter, by changing the dimension of the gap between the lower mirror and the upper mirror, it is possible to transmit light having a wavelength corresponding to the dimension of the gap through the tunable interference filter.
In this wavelength tunable interference filter, Si or Ge is used for the high refractive layer of the optical multilayer mirror, and air is used for the low refractive layer. In such an optical multilayer mirror, the ratio of the refractive indices of the high-refractive layer and the low-refractive layer becomes large, making it possible to provide high reflectance characteristics over a wide band. The variable band also becomes wider.

JP 2009-204381 A

However, in a wavelength tunable interference filter using an optical multilayer mirror, the thicknesses of the high refractive layer and the low refractive layer are usually designed based on the central wavelength λ ₀ of the wavelength tunable band of light that is transmitted through the wavelength tunable interference filter. . That is, when the refractive index of the high refractive layer is _nH , the thickness of the high refractive layer is _dH , the refractive index of the low refractive layer is _nL , and the thickness of the low refractive layer is _dL , the high refractive layer is _{nHdH .} = λ ₀ /4 and the low refractive layer satisfies n _L d _H = λ ₀ /4.
Therefore, when light having a center wavelength of λ ₀ is transmitted through the wavelength tunable interference filter, the spectral characteristic, which is the relationship between the wavelength of the transmitted light and the transmittance, has a narrow half width. In other words, the tunable interference filter can transmit light near the center wavelength _λ0 with high resolution.
However, when transmitting light near a wavelength (edge wavelength) away from the center wavelength λ ₀ in the variable wavelength band, the half-value width in the spectral characteristics becomes wider than when transmitting the center wavelength λ ₀ . In other words, it becomes difficult to transmit the light of the edge wavelength with high resolution from the wavelength tunable interference filter.

An optical device according to a first application example includes a plurality of first optical layers and a plurality of second optical layers having a refractive index different from that of the first optical layers, wherein the first optical layers and the second optical layers an optical member in which layers are laminated; and a layer thickness changing portion that changes the thickness of the first optical layer in the lamination direction of the first optical layer and the second optical layer, wherein the optical member comprises a pair of The pair of optical members are arranged opposite to each other with a gap therebetween, and are provided with a gap changing portion for changing the dimension of the gap.

In the optical device according to this application example, the plurality of first optical layers are fluid layers made of a fluid, and a pair of electrodes are arranged with the first optical layers interposed in the stacking direction. It is preferable that the thickness changing section changes the voltage applied between the pair of electrodes.

In the optical device according to this application example, the plurality of first optical layers are fluid layers made of a fluid, the plurality of second optical layers are conductive, and the layer thickness changing section includes: It is preferable to change the voltage applied between the two second optical layers arranged at both ends with respect to the lamination direction.

An optical device according to a second application example has a plurality of first optical layers, and a plurality of second optical layers made of electro-optic crystals whose refractive index changes according to an applied voltage, and the first optical an optical member configured by laminating a layer and the second optical layer; and a refractive index changing section that changes the refractive index of the second optical layer by changing the voltage applied to the second optical layer. A pair of the optical members are provided, the pair of optical members are arranged opposite to each other with a gap therebetween, and a gap changing portion for changing the dimension of the gap is provided.

In the optical device according to the first application example, the gap changing section changes the dimension of the gap according to the wavelength of light transmitted through the pair of optical members, and the layer thickness changing section changes the thickness of the pair of optical members. It is preferable to change the thickness of the first optical layer according to the wavelength of the light transmitted through the member.

In the optical device according to the second application example, the gap changing section changes the dimension of the gap according to the wavelength of light transmitted through the pair of optical members, and the refractive index changing section changes the size of the pair of optical members. It is preferable that the refractive index of the second optical layer is changed according to the wavelength of light transmitted through the member.

An electronic apparatus according to a third application example includes the optical device according to the first application example or the second application example, and a control unit that controls the optical device.

1 is a schematic diagram showing the configuration of a spectroscopic device according to a first embodiment; FIG. FIG. 4 is a diagram showing a schematic configuration of a first optical member and a second optical member according to the first embodiment; 4 is a flowchart showing a method for driving the spectroscopic device of the first embodiment; FIG. 4 is a diagram showing a mirror structure of a conventional wavelength tunable interference filter as a comparative example; FIG. 4 is a diagram showing spectral characteristics of a wavelength tunable interference filter of a comparative example; FIG. 4 is a diagram showing spectral characteristics of the wavelength tunable interference filter according to the first embodiment; FIG. 4 is a diagram comparing the spectral characteristics of the wavelength tunable interference filter of the first embodiment and the wavelength tunable interference filter of the comparative example; FIG. 5 is a diagram showing the schematic configuration of a first optical member and a second optical member of a wavelength tunable interference filter according to a second embodiment; FIG. 10 is a diagram showing a schematic configuration of a first optical member and a second optical member of a wavelength tunable interference filter according to a third embodiment; FIG. 4 is a diagram showing respective spectral characteristics when target wavelengths are set to 800 nm and 400 nm in the wavelength tunable interference filter of the first embodiment; FIG. 10 is a diagram showing a schematic configuration of a wavelength tunable interference filter according to a modification;

[First embodiment]
A first embodiment will be described below.
FIG. 1 is a schematic diagram showing the configuration of the spectroscopic device of the first embodiment.
[Overall configuration of spectroscopic device 1]
The spectroscopic device 1 is an electronic device that disperses and outputs light of a desired target wavelength set by a user from incident light. The spectroscopic device 1 includes a spectroscopic section 10 which is an optical device and a control section 20, as shown in FIG. Each configuration will be described in detail below.

[Configuration of spectroscopic unit 10]
The spectroscopic section 10 includes a variable wavelength interference filter 11 and a drive circuit 12 for driving the variable wavelength interference filter 11, as shown in FIG.
The tunable interference filter 11 is a Fabry-Perot interferometer and includes a substrate 111 , a first optical member 112 , a second optical member 113 , a gap changing portion 114 and gap forming spacers 115 . The first optical member 112 and the second optical member 113 form a pair of optical members facing each other with an air gap G therebetween.

The first optical member 112 is an optical member provided on the substrate 111 and is an optical multilayer mirror configured by laminating a plurality of optical layers.
The second optical member 113 is an optical member provided on the first optical member 112 via a gap forming spacer 115 or the like, and is an optical multilayer mirror configured by laminating a plurality of optical layers.
A part of the second optical member 113 faces the first optical member 112 with an air gap G therebetween. When the wavelength tunable interference filter 11 is viewed from the stacking direction Z of the optical layers, the portion overlapping the formation position of the air gap G becomes an interference region Ar1 where incident light interferes due to multiple reflection. Transmitted light having a wavelength corresponding to the gap dimension of the air gap G is transmitted through the interference region Ar1 and output from the spectroscopic section 10 .

FIG. 2 is a diagram showing a schematic configuration of the first optical member 112 and the second optical member 113. As shown in FIG.
As shown in FIG. 2, the first optical member 112 and the second optical member 113 each include a plurality of first optical layers 11L and a plurality of second optical layers 11H. The optical layers 11H are alternately laminated along the lamination direction Z of the optical layers.

The first optical layer 11L is a fluid layer made of fluid, and for example, in this embodiment, it is an air layer using air as the fluid.
The second optical layer 11H is made of a solid material having a higher refractive index than the first optical layer 11L, and TiO ₂ , Ta ₂ O ₅ , Si, Ge, etc. can be used, for example.
In order to vary the light transmitted through the wavelength tunable interference filter 11 over a wide band, the refractive index ratio between the first optical layer 11L and the second optical layer 11H is increased. Accordingly, in the reflectance characteristics of the first optical member 112 and the second optical member 113, the wavelength band in which the reflectance is equal to or higher than a predetermined value is widened, and the wavelength variable band Δλ by the spectroscopic section 10 is also widened. In this embodiment, an air layer is used as the first optical layer 11L. In this case, the ratio of the refractive indices of the first optical layer 11L and the second optical layer 11H is greater than when a solid material such as SiO ₂ is used as the first optical layer 11L. Therefore, the wavelength variable band Δλ of the spectroscopic section 10 becomes wider than when a solid material such as SiO ₂ is used as the first optical layer 11L.

Further, in this embodiment, a pair of electrodes 116A and 116B made of a conductive thin film such as ITO is provided on both sides of each first optical layer 11L.
For example, as shown in FIG. 2, both ends of the first optical member 112 in the stacking direction Z are the second optical layers 11H, and both ends of the second optical member 113 in the stacking direction Z are the second optical layers 11H. In this case, the first electrode 116A is provided on the surface of the second optical layer 11H in contact with the first optical layer 11L on the substrate 111 side of the first optical layer 11L. A second electrode 116B is provided on the surface of the second optical layer 11H that is in contact with the first optical layer 11L on the opposite side of the substrate 111 from the first optical layer 11L.
In a cross-sectional view of the wavelength tunable interference filter 11 along the lamination direction Z as shown in FIG. are placed in

A spacer 116C made of a thin film such as SiO ₂ is provided between the first electrode 116A and the second electrode 116B. The spacer 116C is arranged so as to surround the interference area Ar1 at a position that does not overlap with the interference area Ar1 in a cross-sectional view as shown in FIG. At this time, the end of the spacer 116C on the side of the interference region Ar1 is located farther from the interference region Ar1 than the ends of the first electrode 116A and the second electrode 116B on the side of the interference region Ar1. Therefore, the portions of the first electrode 116A and the second electrode 116B that are not in contact with the spacer 116C face each other in the stacking direction Z via the air of the first optical layer 11L. Therefore, when a voltage is applied between the first electrode 116A and the second electrode 116B, the layer thickness of the first optical layer 11L in the interference area Ar1 is reduced due to electrostatic attraction. That is, the first electrode 116A and the second electrode 116B function as a mirror actuator 116 that changes the layer thickness of the first optical layer 11L.
In this embodiment, one mirror actuator 116 is provided for each first optical layer 11L. In other words, mirror actuators 116 are arranged by the number of first optical layers 11L.

By the way, when designing an optical multilayer mirror in which low-refractive layers and high-refractive layers are alternately laminated, the product of the layer thickness and the refractive index of each layer (optical thickness) is the wavelength reflected by the optical multilayer mirror. The layer thickness of each layer is set so as to be 1/4. Further, when the light transmitted from the wavelength tunable interference filter is varied within a predetermined wavelength tunable band Δλ, the optical thickness of each layer is usually 1/4 times the central wavelength λ ₀ in the wavelength tunable band Δλ. Set the layer thickness of each layer.

Also in this embodiment, the layer thickness g2 of the _second optical layer 11H is set so that the optical thickness is 1/4 of the central wavelength _λ0 in the wavelength tunable band Δλ. That is, when n _L is the refractive index of the second optical layer 11H, the optical thickness n _L g ₂ of the second optical layer 11H satisfies n _L g ₂ =λ ₀ /4.
On the other hand, in the present embodiment, the layer thickness g1 of the _first optical layer 11L is such that the optical thickness is the center of the wavelength tunable band Δλ when no voltage is applied between the first electrode 116A and the second electrode 116B. It is set to be larger than 1/4 times the wavelength _λ0 . More preferably, the longest wavelength of the wavelength tunable band Δλ of the spectroscopic section 10 is λ _M , and the layer thickness of the first optical layer 11L when no voltage is applied between the first electrode 116A and the second electrode 116B (initial layer thickness) is g ₁₀ and the refractive index of air n _air is approximated as 1, the initial layer thickness g ₁₀ satisfies g ₁₀ >λ _M /4.
Further, when the maximum voltage is applied between the first electrode 116A and the second electrode 116B, the optical thickness of the first optical layer 11L is smaller than 1/4 times the central wavelength _λ0 in the wavelength tunable band Δλ. is set to be More specifically, the shortest wavelength of the wavelength tunable band Δλ of the spectroscopic section 10 is _λm , and the layer thickness of the first optical layer 11L when the maximum voltage is applied between the first electrode 116A and the second electrode 116B is g ₁₁ , the layer thickness g ₁₁ satisfies g ₁₁ <λ _m /4.

The first optical layer 11L may be a closed space surrounded by the second optical layer 11H, the first electrode 116A, the second electrode 116B, and the spacer 116C. may be configured such that the inside and outside of the are communicated with each other. As a configuration for providing the communicating portion, for example, a plurality of spacers 116C are arranged at intervals so as to surround the interference area Ar1. In this case, a communicating portion is formed between adjacent spacers 116C. Also, a through hole may be provided in the spacer 116C and the through hole may function as a communicating portion.
In the case where the first optical layer 11L has a closed structure, when a voltage is applied to the mirror actuator 116, the air in the first optical layer 11L is compressed and the volume is reduced, and the layer thickness g1 of the _first optical layer 11L is reduced to Change. In addition, in a configuration in which a communicating portion is provided, when a voltage is applied to the mirror actuator 116, the air in the first optical layer 11L escapes to the outside, reducing the volume and changing the layer thickness g1 of the _first optical layer 11L.

Next, the gap changing portion 114 and the gap forming spacer 115 will be described.
The gap changer 114 changes the gap dimension of the air gap G between the first optical member 112 and the second optical member 113 . Specifically, the gap changer 114 includes a third electrode 114A provided on the first optical member 112 and a fourth electrode 114B provided on the second optical member 113. As shown in FIG.
The third electrode 114A is provided on the surface of the first optical member 112 facing the second optical member 113, and is arranged so as to surround the interference area Ar1 in a cross-sectional view along the stacking direction Z.
The fourth electrode 114B is provided on the surface of the second optical member 113 facing the first optical member 112, and is arranged so as to surround the interference region Ar1 in a cross-sectional view along the stacking direction Z, and the third electrode 114A. Oppose.
As shown in FIG. 2, the third electrode 114A may be provided on the first optical member 112 via an optical thin film 117 such as _SiO2 . Similarly, the fourth electrode 114B may be provided on the second optical member 113 via an optical thin film 117 such as _SiO2 .

As shown in FIGS. 1 and 2, the gap forming spacer 115 is arranged between the third electrode 114A and the fourth electrode 114B so as to surround the interference area Ar1 at a position that does not overlap the interference area Ar1. The end of the gap forming spacer 115 on the side of the interference region Ar1 is located farther from the interference region Ar1 than the ends of the third electrode 114A and the fourth electrode 114B on the side of the interference region Ar1. Therefore, the portions of the third electrode 114A and the fourth electrode 114B that are not in contact with the gap forming spacer 115 face each other in the stacking direction Z with the air gap G of the first optical layer 11L interposed therebetween.
In such a gap changer 114, when a voltage is applied between the third electrode 114A and the fourth electrode 114B, the gap dimension of the air gap G is changed by electrostatic attraction. As a result, the wavelength of light passing through the wavelength tunable interference filter 11 is also changed.

[Configuration of drive circuit 12]
Returning to FIG. 1, the drive circuit 12 will be described. As shown in FIG. 1 , the drive circuit 12 includes a mirror drive driver 121 and a filter drive driver 122 .
The mirror driving driver 121 functions as a layer thickness changing unit, is connected to the first electrode 116A and the second electrode 116B of the wavelength tunable interference filter 11, and applies a mirror driving voltage between the first electrode 116A and the second electrode 116B. do. Also, the mirror driving driver 121 changes the electrostatic attraction acting between the first electrode 116A and the second electrode 116B by changing the mirror driving voltage based on the command signal input from the control unit 20. , and the layer thickness g1 of the _first optical layer 11L, which is an air layer, is changed.
Further, in this embodiment, all the first electrodes 116A provided in the tunable interference filter 11 are wired and connected to the mirror driver 121, and all the second electrodes 116B are wired and connected to the mirror driver 121. It is Thereby, the mirror drive driver 121 can apply the same voltage to each mirror actuator 116, and can control the layer thickness g1 of each _first optical layer 11L to be the same thickness.

The filter driving driver 122 is connected to the third electrode 114A and the fourth electrode 114B of the tunable interference filter 11, and applies a filter driving voltage between the third electrode 114A and the fourth electrode 114B.

The drive circuit 12 is driven based on command signals input from the control section 20 . This command signal includes _a mirror driving voltage for setting the layer thickness g1 corresponding to the light of the target wavelength, and a filter driving voltage for setting the gap dimension of the air gap G for transmitting the light of the target wavelength. Contains the voltage command value.
Accordingly, the mirror drive driver 121 applies a mirror drive voltage to the mirror actuator 116 according to the command value of the mirror drive voltage included in the command signal, and the layer thickness g1 of the first optical layer 11L is reduced to _1/4 of the target wavelength. Change it to double.
In addition, the filter driving driver 122 applies a filter driving voltage to the gap changing unit 114 in accordance with the command value of the filter driving voltage included in the command signal, and adjusts the gap dimension of the air gap G to transmit the light of the target wavelength. change in size.

[Configuration of control unit 20]
The control unit 20 is a controller that controls the overall operation of the spectroscopic device 1 . The controller 20 includes a memory 21 and a spectral controller 22, as shown in FIG. The control unit 20 also has an interface (not shown) that connects the spectroscopic device 1 and an external device, and can receive a signal from the external device. As the signal from the external device, for example, a signal designating a target wavelength of light to be dispersed by the spectroscopic device 1 can be exemplified. Note that the spectroscopic device 1 may be configured to have an operation unit that receives an input operation by a user.

Various data for driving the spectroscopic section 10 are recorded in the memory 21 . Specifically, the memory 21 stores a drive table that indicates filter drive voltages and mirror drive voltages for wavelengths of light that is transmitted through the spectroscopic section 10 .

The spectroscopic control section 22 controls the spectroscopic section 10 to change the wavelength of light transmitted through the spectroscopic section 10 .
For example, when a wavelength of light to be dispersed by the spectroscopic unit 10 is input from an external device or an operation unit, the spectroscopic control unit 22 sets the wavelength as the target wavelength. Then, the spectral control unit 22 reads the mirror driving voltage and the filter driving voltage for the target wavelength from the driving table stored in the memory 21 and outputs command signals to the driving circuit 12 .

[Method for Driving Spectroscopic Device 1]
Next, a method for driving the spectroscopic device 1 as described above will be described.
FIG. 3 is a flow chart showing a method of driving the spectroscopic device 1. As shown in FIG.
Here, as an example of driving the spectroscopic device 1, an input signal for dispersing light of a predetermined wavelength is input to the spectroscopic device 1 from an external device (not shown). is changed.
As shown in FIG. 3, the control unit 20 receives from an external device a wavelength designation signal designating a target wavelength _λi to be transmitted through the spectroscopic unit 10 (step S1).
Next, the spectral control unit 22 reads the filter driving voltage and the mirror driving voltage corresponding to the target wavelength λ _i from the driving table recorded in the memory 21 (step S2). Then, the spectral control unit 22 outputs a command signal including the filter driving voltage and the mirror driving voltage to the driving circuit 12 (step S3).

When the command signal is input to the drive circuit 12, the mirror drive driver 121 applies the mirror drive voltage to each mirror actuator 116, and the filter drive driver 122 applies the filter drive voltage to the gap changer 114 (step S4 ).
As a result, the layer thickness g ₁ of the first optical layer 11L constituting the first optical member 112 and the second optical member 113 of the tunable interference filter 11 is changed to λ _i /4. Therefore, the wavelength tunable interference filter 11 can transmit the light of the target wavelength λ _i with a narrow half width, and can transmit the light of the target wavelength with high resolution.

[Spectroscopic measurement of spectroscopic device 1]
Next, the spectral characteristics of the wavelength tunable interference filter 11 in the spectroscopic device 1 of this embodiment will be described using a conventional wavelength tunable interference filter as a comparative example.
FIG. 4 is a diagram showing the mirror structure of the tunable interference filter 90 of the comparative example.
As shown in FIG. 4, the wavelength tunable interference filter 90 of the comparative example has a first optical layer 11L, which is an air layer, and a second optical layer 11H, which is composed of a solid material such as TiO ₂ . It has an optical member 112P and a second optical member 113P. Here, the wavelength tunable interference filter 90 of the comparative example is a filter designed with the visible light range from 400 nm to 700 nm as the wavelength _tunable band _Δλ . and the layer thickness of the second optical layer 11H. That is, in the comparative example, the layer thickness g1 of the _first optical layer 11L is fixed at 125 nm regardless of the wavelength of the light transmitted through the spectroscopic section 10 .

FIG. 5 is a diagram showing spectral characteristics of the wavelength tunable interference filter 90 of the comparative example. Note that FIG. 5 shows respective spectral characteristics when the gap dimension of the air gap G is changed sequentially. In other words, C _P1 is the spectral characteristic when light of 700 nm is transmitted through the tunable interference filter 90 . C _P2 is the spectral characteristic when light of 650 nm is transmitted through the variable wavelength interference filter 90 . C _P3 is the spectral characteristic when light of 600 nm is transmitted through the variable wavelength interference filter 90 . C _P4 is the spectral characteristic when light of 550 nm is transmitted through the variable wavelength interference filter 90 . _CP5 is the spectral characteristic when light of 500 nm is transmitted through the variable wavelength interference filter 90 . _CP6 is the spectral characteristic when light of 450 nm is transmitted through the variable wavelength interference filter 90 . _CP7 is the spectral characteristic when light of 400 nm is transmitted through the variable wavelength interference filter 90 .

In the wavelength tunable interference filter 90 of the comparative example, when the gap dimension of the air gap G is changed so as to transmit the light of the center wavelength λ ₀ , as shown in C _P4 , within a narrow range centered on the center wavelength λ ₀ passes through the tunable interference filter 90 . That is, the half-value width in the spectral characteristics of transmitted light is narrow, and light of the target wavelength can be transmitted with high resolution.
However, when transmitting a wavelength away from the central wavelength λ ₀ , for example, when transmitting light with the shortest wavelength λ _m (=400 nm) or the longest wavelength λ _M (=700 nm) of the variable wavelength band Δλ, C _P1 and _CP7 , the half-value width is larger than that of _CP4 , and the resolution is lowered.

FIG. 6 is a diagram showing spectral characteristics of the wavelength tunable interference filter 11 in this embodiment. Note that FIG. 6 shows respective spectral characteristics when the gap dimension of the air gap G is changed sequentially. In _other words, C1 is the spectral characteristic when light of 700 nm is transmitted through the wavelength tunable interference filter 11 . _C2 is the spectral characteristic when light of 650 nm is transmitted through the wavelength tunable interference filter 11 . C3 is the spectral characteristic when light of 600 nm is transmitted through the wavelength tunable interference filter ₁₁ . _C4 is the spectral characteristic when light of 550 nm is transmitted through the wavelength tunable interference filter 11 . C5 is the spectral characteristic when light of ₅₀₀ nm is transmitted through the wavelength tunable interference filter 11 . C6 is the spectral characteristic when light of 450 nm is transmitted through the wavelength tunable interference filter ₁₁ . C7 is the spectral characteristic when light of 400 nm is transmitted through the wavelength tunable interference filter ₁₁ .
FIG. 7 is a diagram comparing the spectral characteristics of the wavelength tunable interference filter 11 of the present embodiment and the wavelength tunable interference filter 90 of the comparative example. It shows the change in price range. In FIG. 7, T1 is a characteristic curve showing changes in the half-value width of the comparative example, and T2 is a characteristic curve showing changes in the half-value width of the present embodiment.

In the wavelength tunable interference filter 11 of this embodiment, even when the target wavelength is distant from the center wavelength _λ0 , a mirror drive voltage corresponding to the target wavelength is applied to the mirror actuator 116. FIG. Therefore, the reflectance characteristics of the first optical member 112 and the second optical member 113 are optimized with respect to the target wavelength.
In other words, in the present embodiment, the first optical member 112 and the second optical member 113 are in a state where no voltage is applied to the mirror actuator 116, with respect to light in a predetermined wavelength range centered on the longest wavelength _λM . It has a reflectance characteristic in which the reflectance is equal to or higher than a threshold. When the target wavelength is changed, the layer thickness g1 of the _first optical layer 11L is changed according to the target wavelength. shifts to the short wavelength side, and the wavelength range in which the reflectance is equal to or higher than the threshold also shifts to the short wavelength side.
Therefore, as shown in FIGS. 6 and 7, in the wavelength tunable interference filter 11 of the present embodiment, even when light having a wavelength away from the central wavelength _λ0 of the wavelength tunable band Δλ is transmitted, the wavelength tunable interference filter 11 of the comparative example can be transmitted. Compared to the interference filter 90, the half-value width in the spectral characteristics of transmitted light can be narrowed, and light can be transmitted with high resolution.

[Action and effect of the present embodiment]
The spectroscopic device 1 of this embodiment includes a spectroscopic section 10 having a variable wavelength interference filter 11 and a drive circuit 12 and a control section 20 .
The variable wavelength interference filter 11 constituting the spectroscopic section 10 changes the gap dimension of the first optical member 112, the second optical member 113, and the air gap G between the first optical member 112 and the second optical member 113. and a gap changer 114 .
The first optical member 112 and the second optical member 113 each have a plurality of first optical layers 11L and a plurality of second optical layers 11H having a refractive index different from that of the first optical layer 11L. The optical layer 11L and the second optical layer 11H are laminated.
Further, the driving circuit 12 constituting the spectroscopic section 10 includes a mirror driving driver 121 functioning as a layer thickness changing section, and the mirror driving driver 121 changes the layer thickness g1 of the _first optical layer 11L.

Therefore, in this embodiment, by changing the layer thickness g1 of the _first optical layer 11L, it is possible to change the optical characteristics (reflectance characteristics) of the first optical member 112 and the second optical member 113. . That is, by changing the layer thickness g1, it is possible to shift the center wavelength of the reflectance characteristics of the _first optical member 112 and the second optical member 113 so as to approach the target wavelength.
As a result, when the light of the target wavelength is transmitted through the tunable interference filter 11, the half width in the spectral characteristics of the transmitted light is narrowed, and the light of the target wavelength can be transmitted with high resolution.
Further, by changing the layer thickness g1 of the _first optical layer 11L, it is possible to shift the center wavelength of the reflectance characteristics of the first optical member 112 and the second optical member 113. The wavelength range of light that can be reflected by the second optical member 113 is widened. Therefore, the variable wavelength band Δλ of the variable wavelength interference filter 11 can be widened.

Furthermore, in the spectroscopic device 1 including such a spectroscopic unit 10, by outputting a command signal to the spectroscopic unit 10 from the control unit 20, the wavelength of the light transmitted by the spectroscopic unit 10 can be easily controlled. The spectroscopic device 1 can emit light of a target wavelength with high resolution.

In the wavelength tunable interference filter 11 of this embodiment, the first optical layer 11L is an air layer (fluid layer), and the first electrode 116A and the second electrode 116B are arranged with the first optical layer 11L interposed therebetween. A mirror actuator 116 is configured by the first electrode 116A and the second electrode 116B. The mirror drive driver 121 changes the layer thickness g1 of the _first optical layer 11L by changing the mirror drive voltage applied to the mirror actuator 116 provided in each first optical layer 11L.
That is, of the pair of second optical layers 11H sandwiching the first optical layer 11L, one of the second optical layers 11H arranged on the substrate 111 side is provided with the first electrode 116A. Further, the second electrode 116B is provided on the second optical layer 11H arranged on the other of the pair of second optical layers 11H on the side opposite to the substrate 111 .
In such a configuration, by controlling the mirror drive voltage to the mirror actuator 116, the second optical layer 11H to which the first electrode 116A is bonded and the second optical layer 11H to which the second electrode 116B is bonded are They are stressed toward each other by electrostatic attraction. Also, since the first optical layer 11L is made of air (fluid), the second optical layers 11H sandwiching the first optical layer 11L are easily displaced in the direction of approaching each other. This makes it possible to easily change the layer thickness g1 of the _first optical layer 11L.

At this time, in the present embodiment, the filter driving driver 122 applies a filter driving voltage corresponding to the target wavelength to the gap changing unit 114, and the mirror driving driver 121 causes the mirror actuator 116 to apply a mirror voltage corresponding to the target wavelength. Apply the drive voltage.
That is, the gap changer 114 changes the gap dimension of the air gap G to a dimension that allows the light of the target wavelength to pass therethrough by applying a filter driving voltage corresponding to the target wavelength. Thereby, the light of the target wavelength is transmitted from the wavelength tunable interference filter 11 .
A mirror drive voltage is applied to the mirror actuator 116 to make the layer thickness g1 of the first optical layer 11L _1/4 times the target wavelength. Thereby, the reflectance characteristics of the first optical member 112 and the second optical member 113 can be shifted to the target wavelength side.
Therefore, it is possible to output light with a narrow half-value width centered on the light of the target wavelength from the wavelength tunable interference filter 11 .

[Second embodiment]
Next, a second embodiment will be described.
In the first embodiment, the first electrode 116A and the second electrode 116B are arranged for each first optical layer 11L in order to change the layer thickness g1 of the _first optical layer 11L. In contrast, the present embodiment differs from the first embodiment in that the second optical layer 11H is used as an electrode and the layer thickness g1 of the _first optical layer 11L is changed.
In the description below, the same components are denoted by the same reference numerals, and their descriptions are omitted or simplified.

FIG. 8 is a diagram showing the mirror configuration of the tunable interference filter 11A of the second embodiment, that is, the schematic configuration of the first optical member 112A and the second optical member 113A.
In this embodiment, the wavelength tunable interference filter 11 shown in FIG. 2 is changed to a wavelength tunable interference filter 11A shown in FIG. 8 in the spectroscopic section 10 of the first embodiment.
As shown in FIG. 8, a tunable interference filter 11A has a substrate 111 on which a first optical member 112A is provided, and an air gap G between the first optical member 112A and the first optical member 112A. Two optical members 113A are arranged to face each other.

The first optical member 112A and the second optical member 113A are each provided with a plurality of first optical layers 11L and a plurality of second optical layers 11H, similarly to the first embodiment. The optical layers 11H are alternately laminated along the lamination direction Z of the optical layers.
Here, in this embodiment, the second optical layer 11H has conductivity. As such a second optical layer 11H, for example, a conductive solid material such as ITO, Si, or Ge can be used. Also, an optical material such as TiO ₂ may be doped with, for example, Nb, Ta, or the like to have conductivity.

In this embodiment, the spacers 116C are arranged directly between the plurality of second optical layers 11H to form the first optical layer 11L with an initial layer thickness _g10 corresponding to the thickness of the spacers 116C.
In addition, in the present embodiment, the second optical layers 11H are arranged at both ends in the lamination direction Z of the first optical member 112A, and the second optical layers 11H arranged at both ends in the lamination direction Z are It is electrically connected to the mirror driving driver 121 .
Similarly, the second optical layers 11H are arranged at both ends in the stacking direction Z of the second optical member 113A, and the second optical layers 11H arranged at both ends in the stacking direction Z are mirror driving drivers 121. is electrically connected to
In such a configuration, each second optical layer 11H functions as a capacitor electrically connected in series, and when a mirror driving voltage is applied by the mirror driving driver 121, each capacitor retains electric charge. At this time, since the amount of charge held in each capacitor is the same, electrostatic attraction causes the same amount of displacement between the second optical layers 11H, making the layer thickness g1 of the _first optical layer 11L uniform. It can be changed to any desired dimension.

[Action and effect of the present embodiment]
In the present embodiment, the first optical member 112A and the second optical member 113A each have a first optical layer 11L, which is an air layer (fluid layer), and a conductive second optical layer 11H. are alternately laminated. Then, the mirror driving driver 121 applies a mirror driving voltage between the two second optical layers 11H arranged at both ends in the stacking direction Z of the first optical member 112A.
In such a configuration, the plurality of second optical layers 11H arranged on the first optical member 112A become parallel plates arranged via the first optical layer 11L, which is an air layer, and are electrically connected in series. acts as a capacitor for Since these capacitors hold the same amount of charge, the layer thickness g1 of the _first optical layer 11L is maintained at the same dimension. Moreover, since the electrostatic attraction corresponding to the mirror drive voltage is also equal for each capacitor, the layer thickness g1 of the _first optical layer 11L can be changed by the same amount.
Therefore, in the present embodiment, as in the first embodiment, the layer thickness g1 of each first optical layer 11L can be adjusted to a dimension corresponding to the target wavelength, and the layer thickness g of each _first optical layer 11L can be adjusted. ₁ can be precisely controlled to have the same dimensions with a simple configuration.

[Third embodiment]
Next, a third embodiment will be described. In the first embodiment and the second embodiment, an example of changing the layer thickness g1 of the _first optical layer 11L, which is the fluid layer, is shown. On the other hand, the third embodiment differs from the first and second embodiments in that the optical thickness is changed by changing the refractive index of the optical layer that constitutes the optical member.

FIG. 9 is a diagram showing the schematic configuration of the first optical member 112B and the second optical member 113B of the wavelength tunable interference filter 11B of the third embodiment.
As shown in FIG. 9, the wavelength tunable interference filter 11B of this embodiment has a first optical member 112B provided on a substrate 111, and a second optical member 112B with an air gap G therebetween. 113B are arranged to face each other.

The first optical member 112B and the second optical member 113B include a plurality of first optical layers 11L and a plurality of second optical layers 11H, and the first optical layer 11L and the second optical layer 11H are the optical layers. It is configured by alternately stacking along the stacking direction Z. FIG.
Here, in the present embodiment, the second optical layer 11H is an electro-optic crystal made up of, for example, a liquid crystal cell, and its refractive index changes by applying a voltage. That is, in the present embodiment, the layer thickness g2 of the _second optical layer 11H is fixed, and the optical thickness _nLg of the second optical layer 11H is changed by changing the refractive index _nL of the second optical layer 11H. ₂ is controlled to be 1/4 times the target wavelength.

In this embodiment, the drive circuit 12B includes a refractive index changer 123. FIG. The refractive index changing section 123 is connected to each second optical layer 11H and changes the voltage (refractive index control voltage) applied to each second optical layer 11H.
Furthermore, in the present embodiment, the memory 21 of the control unit 20 stores a target wavelength, a filter drive voltage corresponding to the target wavelength, and an optical thickness n _L g ₂ of the second optical layer 11H as a drive table. and a refractive index control voltage to be applied to the second optical layer 11H for setting the refractive index to 1/4 of . Therefore, when receiving a wavelength designation signal designating a target wavelength from an external device or the like, the spectral control unit 22 reads out the filter driving voltage and the refractive index control voltage corresponding to the target wavelength from the driving table, and the driving circuit A command signal is output to 12B. Thereby, the filter driving driver 122 of the driving circuit 12B drives the gap changer 114 so that the gap dimension of the air gap G becomes the dimension corresponding to the target wavelength. Further, the refractive index changing section 123 of the drive circuit 12B changes the refractive index _nL so that the optical thickness _nLg2 of the _second optical layer 11H becomes 1/4 times the target wavelength.

In the tunable interference filter 11B of this embodiment shown in FIG. 9, the mirror actuator 116 is not arranged for each first optical layer 11L, and the layer thickness g1 of the _first optical layer 11L is constant. but not limited to this.
For example, like the first embodiment and the second embodiment, the thickness dimension of the first optical layer 11L may be changeable. At this time, in this embodiment, when a voltage is applied to the second optical layer 11H, the refractive index of the second optical layer 11H changes. Therefore, as in the first embodiment, the first electrode 116A is arranged on one side of the pair of second optical layers 11H sandwiching the first optical layer 11L, and the second electrode 116B is arranged on the other side to form the mirror actuator 116. preferably.
In such a configuration, the mirror driver 121 of the drive circuit 12 changes the layer thickness g1 of the _first optical layer 11L so that the optical thickness of the first optical layer 11L becomes 1/4 of the target wavelength. Also, the refractive index changing unit 123 changes the refractive index n _L such that the optical thickness n _L g ₂ of the second optical layer 11H is 1/4 times the target wavelength.

[Action and effect of the present embodiment]
The spectroscopic section 10 of this embodiment includes a variable wavelength interference filter 11B and a drive circuit 12B. In the tunable interference filter 11B of the present embodiment, the first optical member 112 and the second optical member 113 each have a plurality of first optical layers 11L and a plurality of second optical layers 11H. A layer 11L and a second optical layer 11H are laminated. The second optical layer 11H is made of an electro-optical crystal such as liquid crystal, and its refractive index changes with voltage application.
A refractive index changing section 123 is provided in the drive circuit 12B, and the refractive index changing section 123 changes the refractive index of the second optical layer 11H by changing the voltage applied to the second optical layer 11H. Let
It also has a gap changer 114 that changes the gap dimension of the air gap G between the first optical member 112 and the second optical member 113 .

Therefore, in the present embodiment, by changing the refractive index n _L of the second optical layer 11H so that the optical thickness n _L g ₂ of the second optical layer 11H is 1/4 times the target wavelength, It is possible to shift the central wavelength in the reflectance characteristics of the first optical member 112B and the second optical member 113B so as to approach the target wavelength.
As a result, when the light of the target wavelength is transmitted from the wavelength tunable interference filter 11B, the half width in the spectral characteristics of the transmitted light can be narrowed, and the light of the desired target wavelength can be transmitted with high resolution.

[Modification]
It should be noted that the present invention is not limited to the above-described embodiments, and includes modifications, improvements, etc. within the scope of achieving the object of the present invention.

[Modification 1]
In the above-described first embodiment, the spectroscopic device 1 that disperses and outputs the light of the target wavelength is exemplified as the electronic device, and the spectroscopic unit 10 including the wavelength tunable interference filter 11 and the driving circuit 12 is exemplified as the optical device. , but not limited to.
For example, the electronic device may be a spectroscopic measurement device that disperses light from a measurement target using the spectroscopic unit 10 and measures the dispersive light. Such a spectrometry device can be incorporated in, for example, a printer that prints an image on a printing medium, a projector that projects image light onto a screen, or the like.

Moreover, although the optical device is the spectroscopic section 10 and the configuration including the variable wavelength interference filter 11 including the first optical member 112 and the second optical member 113 has been exemplified, the present invention is not limited to this. For example, the optical device may be a mirror device that includes one optical member and reflects incident light incident on the optical member in a predetermined direction.

Furthermore, the optical member need not be a mirror that reflects light, and may be, for example, an antireflection film or a cut filter that cuts light of a predetermined wavelength. That is, the optical member in which the first optical layers 11L and the second optical layers 11H are alternately laminated reflects part of the light and transmits the other part of the light. Therefore, it functions as an antireflection film (AR coat) in the transmission wavelength range. By changing the optical thickness of the first optical layer 11L and the second optical layer 11H, as in each of the above-described embodiments, it is possible to shift the center wavelength and reflection wavelength range of the reflectance characteristics, thereby increasing the AR It is also possible to shift the anti-reflection wavelength range in which the coat prevents reflection.

[Modification 2]
In the first embodiment, as a driving method of the spectroscopic device 1, the spectroscopic device 1 is driven so as to transmit light of a target wavelength based on a wavelength designation signal input from an external device or the like.
On the other hand, for example, the control unit 20 may control a plurality of wavelengths from the longest wavelength λ _M to the shortest wavelength λ _m so that they are sequentially transmitted at a predetermined cycle. In this case, the controller 20 may sequentially input the command signal for each wavelength to the drive circuit 12 .
In this case, it is also possible to calculate the spectral spectrum of the measurement light by causing the light receiving unit to receive light of a plurality of wavelengths emitted from the spectroscopic device 1 and measuring the amount of received light for each wavelength.

[Modification 3]
In the second embodiment, the mirror driving driver 121 applies a mirror driving voltage between the second optical layers 11H positioned at both ends in the stacking direction Z of the first optical member 112A, and similarly applies the mirror driving voltage to the second optical member 113A. A mirror driving voltage was applied between the second optical layers 11H positioned at both ends in the stacking direction Z of the .
On the other hand, the mirror drive driver 121 is arranged to move the second optical layer 11H closest to the substrate 111 of the first optical member 112A and the second optical layer 11H farthest from the substrate 111 of the second optical member 113A. and a mirror driving voltage may be applied between these two second optical layers 11H.

In such a configuration, the gap dimension of the air gap G can also be changed by applying the mirror driving voltage. In this case, the initial layer thickness _g10 of the first optical layer 11L is set to be 1/4 times the longest wavelength _λM of the wavelength tunable band Δλ, and the gap dimension of the air gap G is equal to the target wavelength. A mirror driving voltage is applied so that the dimensions are such that light can be transmitted. Thereby, the air gap G can be changed to a dimension corresponding to the target wavelength, and the layer thickness g1 of the _first optical layer 11L can be reduced as the target wavelength becomes smaller. Therefore, compared with the conventional wavelength tunable interference filter in which the layer thickness of the first optical layer 11L is fixed, the half width in the spectral characteristics of transmitted light can be reduced, and the resolution can be improved.

[Modification 4]
Although the first optical layer 11L is an air layer in the third embodiment, it is not limited to this.
For example, the first optical layer 11L may be an optical layer using a solid material such as _SiO2 .
Furthermore, both the first optical layer 11L and the second optical layer 11H may be composed of electro-optic crystals. In this case, the first optical layer 11L uses an electro-optic crystal that can change the refractive index within a first refractive index range that is greater than or equal to the first refractive index and less than the second refractive index, and the second optical layer 11H uses the second An electro-optic crystal whose refractive index can be changed within a second refractive index range from a third refractive index higher than the refractive index to less than a fourth refractive index higher than the second refractive index is used. Then, the _first optical layer 11L and the _second optical layer 11H are formed so that the layer thickness g1 of the _first optical layer 11L and the layer thickness g2 of the _second optical layer 11H satisfy g1>g2. .
In this case, in both the first optical layer 11L and the second optical layer 11H, the optical thickness can be changed to a value according to the target wavelength, and the wavelength tunable interference filter can transmit light of the target wavelength with higher resolution. can be permeated.

[Modification 5]
In the first embodiment and the second embodiment, when the layer thickness g1 of the _first optical layer 11L is changed, light having a wavelength other than the target wavelength within the wavelength tunable band Δλ is transmitted through the tunable interference filters 11 and 11A. I have something to do.
FIG. 10 is a diagram showing respective spectral characteristics when the target wavelengths are set to 800 nm and 400 nm in the wavelength tunable interference filter 11 of the first embodiment. In FIG. 10, T3 is the spectral characteristic for 800 nm, and T4 is the spectral characteristic for 400 nm.
As indicated by T3 in FIG. 10, when the target wavelength is 800 nm and the layer thickness g1 of the _first optical layer 11L and the gap dimension of the air gap G are changed, the wavelength tunable interference filter 11 outputs a target wavelength of 800 nm. , and light with a wavelength of 550 nm or less is also transmitted through the variable wavelength interference filter 11 at the same time. Further, as indicated by T4, when the target wavelength is 400 nm and the layer thickness g1 of the _first optical layer 11L and the gap dimension of the air gap G are changed, light with a target wavelength of 400 nm is emitted from the wavelength tunable interference filter 11. In addition, light with a wavelength of 650 nm or more is also transmitted through the variable wavelength interference filter 11 at the same time.

Therefore, a cut filter that blocks light in a predetermined wavelength range may be inserted on the optical axis of the wavelength tunable interference filter 11 of the spectroscopic section 10, and the cut filter may be replaced according to the target wavelength.
For example, in order to transmit light with a target wavelength of 800 nm through the variable wavelength interference filter 11 , a first cut filter that blocks light with a wavelength of 550 nm or less is inserted on the optical axis of the variable wavelength interference filter 11 .
Further, when the light with the target wavelength of 400 nm is to be transmitted from the wavelength tunable interference filter 11, the first cut filter is retracted from the optical axis of the wavelength tunable interference filter 11, and instead, the second cut filter that blocks light of 650 nm or longer is used. Insert a cut filter.
As a result, the problem that wavelengths other than the target wavelength are emitted from the spectroscopic device 1 can be suppressed.

[Modification 6]
In the first embodiment, an example was shown in which the mirror actuators 116 arranged in each of the first optical layers 11L are connected in parallel and the mirror driving voltage is applied, but the present invention is not limited to this. For example, each mirror actuator 116 may be electrically connected in series as in the second embodiment. In this case, the first electrode 116A and the second electrode 116B of the adjacent mirror actuators 116 are electrically connected, and the first electrode 116A of the mirror actuator 116 arranged at the end on the substrate 111 side with respect to the stacking direction Z, and The second electrode 116B of the mirror actuator 116 arranged at the end opposite to the substrate 111 may be connected to the mirror driver 121 .

[Modification 7]
In the first embodiment and the second embodiment, an example in which the first optical layer 11L is an air layer is shown, but the present invention is not limited to this. The first optical layer 11L may be composed of a liquid such as water or a gas such as He. Since the first optical layer 11L is composed of the fluid layer in this way, the layer thickness g of the first optical layer 11L can be increased with less stress than when the first optical layer 11L is composed of a solid material. ₁ can be changed.
Note that a configuration in which a solid material is used as the first optical layer 11L may be employed. In this case, for example, as in the second embodiment, the thickness of the first optical layer 11L is changed by pressing the first optical layer 11L with a pair of second optical layers 11H that sandwich the first optical layer 11L. good too.

[Modification 8]
In the above embodiment, the first optical member 112 is laminated on the substrate 111, and the configuration example of the wavelength tunable interference filters 11, 11A, and 11B in which the second optical member 113 is laminated via the gap forming spacer 115 is shown. However, it is not limited to this.
For example, a configuration in which the gap forming spacer 115 is not provided may be adopted. That is, the first optical member 112 is provided on the substrate 111, a part of the second optical member 113 is bonded onto the first optical member 112, and the other part of the second optical member 113 is the first optical member. A configuration in which the member 112 is separated from the member 112 via an air gap G may be employed. To form such a tunable interference filter, for example, after forming the first optical member 112 and the third electrode 114A on the substrate 111, a sacrificial layer is formed on a part of the first optical member 112. FIG. Then, a fourth electrode 114B is formed on the sacrificial layer, and a second optical member 113 is formed on the first optical member 112 so as to cover the entire sacrificial layer. The second optical member 113 is joined, and finally the sacrificial layer is removed by etching or the like. Thereby, it is possible to form a variable wavelength interference filter in which the first optical member 112 and the second optical member 113 face each other without a spacer or the like.

Also, FIG. 11 is a schematic cross-sectional view showing the configuration of a wavelength tunable interference filter 11C having two substrates.
Like the wavelength tunable interference filter 11C shown in FIG. 11, the first substrate 51 is provided with the first optical member 112, the second substrate 52 is provided with the second optical member 113, and the first substrate 51 and the second substrate 52 are may be joined by the joining layer 53 . In this case, it is preferable to form a movable portion 521 on which the second optical member 113 is provided and a diaphragm 522 that displaces the movable portion 521 toward the first substrate 51 on the second substrate 52 . Further, by forming the third electrode 114A constituting the gap changing portion 114 on the first substrate 51 and forming the fourth electrode 114B on the second substrate 52, the interference area Ar1 can be expanded.

In the above embodiment, an example in which the gap changer 114 is configured by the third electrode 114A and the fourth electrode 114B is shown, but the present invention is not limited to this.
For example, a piezoelectric body may be arranged between the first optical member and the second optical member, and the gap dimension of the air gap G may be changed by changing the voltage applied to the piezoelectric body. Alternatively, a sealed space may be provided between the first optical member and the second optical member, and the gap dimension of the air gap G may be changed by changing the pressure in the sealed space.

In addition, the specific structure for carrying out the present invention can be appropriately changed to another structure or the like as long as the object of the present invention can be achieved.

DESCRIPTION OF SYMBOLS 1... Spectroscopic device (electronic device), 10... Spectroscopic part (optical device), 11, 11A, 11B, 11C... Variable wavelength interference filter, 11H... Second optical layer, 11L... First optical layer, 12, 12B... Drive Circuit 20 Control unit 21 Memory 22 Spectral control unit 111 Substrate 112, 112A, 112B First optical member 113, 113A, 113B Second optical member 114 Gap changing unit 114A ... third electrode 114B ... fourth electrode 115 ... gap forming spacer 116 ... mirror actuator 116A ... first electrode 116B ... second electrode 116C ... spacer 117 ... optical thin film 121 ... mirror driving driver (layer Thickness changing part), 122... Filter driving driver, 123... Refractive index changing part, Ar1... Interference area, G... Air gap, Z... Stacking direction, g1... Layer thickness of _first optical layer, g2... _Second optical Layer thickness.

Claims (3)

an optical member having a plurality of first optical layers and a plurality of second optical layers having a refractive index different from that of the first optical layers, wherein the first optical layers and the second optical layers are laminated;
a layer thickness changing unit that changes the thickness of the first optical layer in the stacking direction of the first optical layer and the second optical layer,
A pair of the optical members are provided,
The pair of optical members are arranged to face each other across a gap,
A gap changing unit that changes the dimension of the gap ,
the plurality of first optical layers are fluid layers composed of a fluid;
The plurality of second optical layers have conductivity,
The optical device , wherein the layer thickness changing section changes a voltage applied between the two second optical layers arranged at both ends in the stacking direction . An optical device according to claim 1 , wherein
The gap changing unit changes the dimension of the gap according to the wavelength of light transmitted through the pair of optical members,
The optical device, wherein the layer thickness changing section changes the thickness of the first optical layer according to the wavelength of light transmitted through the pair of optical members. an optical device according to claim 1 or claim 2 ;
a control unit that controls the optical device;
An electronic device comprising:

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